The present invention concerns an aqueous composition for rendering a substrate hydrophobic, as well as the use of this composition and a process for rendering the aforementioned substrate hydrophobic.
It is well known that the application of hydrophobing agents (namely substances, in the present description, that render the substrate water repellant), on an arid soil permits a substantial economy of water, because the treated surface presents an efficient barrier against the evaporation of irrigation water. European patent application 889,109 discloses the use of sodium or potassium methylsiliconate to render a substrate hydrophobic. This process, however, presents two disadvantages. First, the quantity of water needed to apply the methylsiliconate on a given surface is too great (about 10 to 20 m3/hectare) and second, the cost of methylsiliconates is high, limiting the use of the process in many cases due to economic reasons. Thus, there is a need for improvement in this area.